1. Industrial Field of Utilization
The present invention relates generally to a technology for simulating an acoustic space in which a sound source for generating sounds and a sound receiving point for listening to the sounds generated by this sound source are arranged.
2. Prior Art
Technologies have been proposed in which the acoustic characteristics of a particular acoustic space are simulated by the addition of reverberation to inputted sounds, for example. In this type of simulation, a path along which a sound generated by a sound source travels to a sound receiving point must be specified (this path hereinafter referred to as a transmission path). For the determination of this transmission path, a so-called mirror image method is in wide use. The mirror image method assumes an mirror image of a sound source arranged in an acoustic space, relative to one of walls forming this acoustic space and, on the basis of the position of this mirror image, the mirror image method determines a reflective point of the sound and a sound transmission path extending from the sound source to the sound receiving point (refer to patent document 1 below for example).
Patent document 1 is Japanese Published Unexamined Patent Application No. Hei 8-286690 (refer to paragraphs 0004 through 0007 and FIGS. 5 and 6)
However, some of the mirror images assumed by the mirror image method correspond to transmission paths which do not exist in the actual acoustic space. Therefore, it is necessary to determine whether each mirror image assumed in the acoustic space can establish a true transmission path, which results in an increased amount of computation required for carrying out simulations. Especially, in the case where the positional relationship between the sound source and the sound receiving point within an acoustic space changes with time, it becomes necessary, every time the change takes place, to re-determine whether the mirror image establishes the true transmission path, thereby making more conspicuous the problem of the increased amount of simulation computation.